Stick Welding Electrodes

A breakdown of electrode coatings, AWS classification, and the underlying characteristics that determine how a rod actually behaves.

DJR Welding LLC  ·  April 2026  ·  7 min read

Why is 6010 so violent but 7018 welds as smooth as butter? The easy answer is the flux composition. But we’re not going to settle for the easy answer. Understanding what’s actually in these coatings — and what those materials do when they burn — is what this post is about.

1. What the coating actually does

Every stick electrode has a flux coating wrapped around the metal core. That coating does three primary things: it shields the weld pool from the atmosphere, provides deoxidizers and arc stabilizers, and forms a slag that protects the bead as it solidifies.

Second — deoxidizers and arc stabilizers. These refine the weld metal, help maintain a stable arc, and produce a cleaner, stronger deposit.

Third — slag. The slag coating that forms over the finished weld manages the cooling rate and protects the weld as it solidifies. How the weld cools directly affects its mechanical properties.

The coating isn’t just there to make the rod easier to use. It’s doing chemistry while you weld.

2. Reading the AWS classification code

The American Welding Society — AWS — developed a classification system for stick electrodes. If you’ve welded before you’ve seen numbers like E7018 and E6010. Here’s what they mean.

Example: E7018 decoded above. The last digit tells you the most about how the rod will actually behave.

The first two digits — or three digits in higher tensile strength rods — indicate the minimum tensile strength of the deposited weld metal in thousands of pounds per square inch. A 60 series rod deposits weld metal with a minimum tensile strength of 60,000 PSI. A 70 series rod deposits at 70,000 PSI minimum. These are the two most common in general structural welding on low carbon steel.

The next to last digit indicates the welding positions the rod is designed for. A 1 means the rod can be run in all positions — flat, horizontal, vertical, and overhead. A 2 means flat and horizontal only.

The last digit indicates coating type and usability characteristics, including current type and polarity the rod is designed to run on. This is the number that tells you the most about how the rod will actually behave.

3. The three main coating types

For most applications welding on low carbon steel, stick electrodes fall into three groups: cellulosic, rutile, and low hydrogen. Understanding what each group is made of is what makes the behavior of each rod make sense.

Cellulosic — 6010

Cellulosic electrodes like the 6010 get their characteristics from what’s in the coating. The organic wood-based material — wood flour, sawdust, wood pulp — is naturally high in moisture. When that coating burns it produces high hydrogen and generates a higher arc voltage compared to other electrode types. That combination creates a forceful, penetrating arc with a fast-freezing slag that gives 6010 its characteristic dig and root control. The same high hydrogen that drives those arc characteristics is also why 6010 isn’t the right choice for crack-sensitive steels.

That combination of arc force and fast-freezing slag is what allows 6010 to burn through mill scale, rust, and poorly cleaned base metal and still place a sound weld. The fast freeze keeps the puddle controlled even in difficult positions and is what makes downhill welding possible with 6010 — useful in pipeline work and other field applications.

The trade-off is amperage. The high-energy arc characteristics of cellulosic rods mean they tend to be run at lower amperages compared to 7018.

Low Hydrogen — 7018

7018 uses a basic low-hydrogen coating, commonly containing limestone and other calcium-based materials along with iron powder. The iron powder addition allows for higher deposition rates and contributes to the smooth, fluid arc that 7018 is known for.

Because the coating contains no cellulose, low hydrogen rods produce significantly less diffusible hydrogen in the weld deposit. That’s the point. But it comes with a requirement — these rods need to be kept away from moisture. If a 7018 absorbs moisture it can no longer be relied on as a low-hydrogen electrode. That’s why you keep them in a rod oven or a sealed container.

Beyond the hydrogen characteristics, 7018 also has higher tensile strength and better ductility than 6010. The weld deposit is tougher, more flexible, and better able to handle dynamic loading and vibration.

Rutile — 6013

Rutile electrodes — like the 6013 — are composed primarily of rutile, a natural form of titanium dioxide. This composition produces a medium penetrating arc and is well known for its user-friendliness. The arc is stable and forgiving, the slag is easy to remove, and the rod is generally considered the most approachable for beginners.

Rutile electrodes are generally not low-hydrogen electrodes, so they are not the first choice where hydrogen cracking is a concern. The 6013 is a versatile rod — it can run on DCEP, DCEN, or AC — but it’s generally better suited to lighter structural work and sheet metal rather than heavy structural applications where 7018 is the right choice.

4. 6010 vs 7018 — mechanical properties and why they differ

6010 is built for situations where penetration on unclean or poorly prepared metal is the priority. It digs, handles dirty metal, and can be run downhill. But the same coating characteristics that make it aggressive in the arc create limitations in the finished weld.

Toughness and ductility are where 7018 clearly outperforms 6010. 7018 generally produces weld metal with better toughness and ductility than 6010, especially in low-hydrogen applications. 6010 is less suitable than 7018 for critical restrained joints because it leaves more diffusible hydrogen in the weld area.

7018 is better suited to structures subject to cyclic loading, restraint, and service stresses because its low-hydrogen deposit offers better crack resistance and toughness. 7018 produces a tougher, more ductile weld deposit that performs better under vibration and dynamic loading. 6010, while excellent for penetration and root passes, is not intended for those types of applications.

Characteristic comparison — 6010 vs 7018

5. Side-by-side comparison

6. In the field

Wrong electrode selection doesn’t always announce itself immediately. What it looks like is a weld that passes visual inspection and fails in service — a joint that cracks under load, a repair that holds for six months and then opens up, a structural connection made with the wrong rod because it was what was on the truck.

Mild steel is relatively forgiving. Most mistakes in electrode selection on mild steel won’t produce immediate visible failure. But when welding on other base metals — hardened steel, high carbon steel, or manganese steel — the stakes change significantly. These materials are far more sensitive to hydrogen and heat input and require a much more careful approach to electrode selection, preheat, and procedure. We’ll cover welding on those materials in a future post in this series.

Understanding why each rod behaves the way it does — what’s in the coating, what that produces, and what that means for the finished weld — is what allows a welder to make the right call in the field. Having a team that understands electrode selection at this level is what prevents failures before they happen. That’s what saves a company time and money.

7. Quick Reference

• 6010 — Cellulosic — high hydrogen · aggressive digging arc · deep penetration · fast freeze slag · tolerates dirty metal · capable of downhill · lower tensile strength · more brittle · prone to hydrogen cracking
• 7018 — Low Hydrogen — calcium carbonate coating · iron powder addition · smooth fluid arc · high deposition rate · must be kept dry · higher tensile strength · better ductility · preferred for structural work
• 6013 — Rutile — titanium dioxide coating · medium penetration · user friendly · easy slag removal · runs on DCEP, DCEN, or AC · better suited to lighter work

8. Questions we hear on this

9. TLDR — Key Facts

Questions on this or topics you want covered next — drop them in the comments or reach out directly. More coming.